Site Search Navigation

Site Navigation

Site Mobile Navigation

Gubernatorial Forecast Update

By Nate Silver September 16, 2010 6:20 amSeptember 16, 2010 6:20 am

There is little aggregate change in the FiveThirtyEight gubernatorial forecast since the previous model run on Sept. 3. On average, over the course of 100,000 simulations, Republicans were projected to control 30.2 governorships after the Nov. 2 elections, up incrementally from 30.1 two weeks ago. Democrats were projected to control the governorships in an average of 19.5 states.

There are some material changes, however, in individual states:

In California, the Republican, Meg Whitman, has emerged with a somewhat clearer lead over the Democrat, Jerry Brown, as each of the five polls released within the past month have given her a single-digit advantage. Mr. Brown still has better than a 1-in-3 chance of winning the race, however.

In Michigan, Democratic chances are also down. Although the Republican, Rick Snyder, already had a double-digit lead in the polling, many polls had also shown a large number of undecided voters, which suggested that the race might tighten. But a new poll, from The Detroit News, gives Mr. Snyder a 20-point lead with few undecided voters. The Democratic candidate, Virg Bernero, now has less than a 10 percent chance of winning.

Several new polls in Florida show the Democrat, Alex Sink, with a lead. Ms. Sink’s chances were perhaps bolstered by the endorsement of Lawton Chiles III, who had been running as an independent before dropping out on Sept. 2. Like Ms. Whitman in California, Ms. Sink could easily lose, but there is now enough evidence to call her the favorite.

There has not been much polling, on the other hand, in Maine, where a conservative Republican who has the support of the Tea Party, Paul LePage, is running against the Democrat Elizabeth Mitchell. But a new poll from Public Policy Polling gives Mr. LePage a 14-point advantage, which has improved his winning chances in our model to about 80 percent, from 60 percent. This is one of those calls that I have a bit of doubt about: Maine can certainly elect moderate Republicans, like the Senators Olympia J. Snowe and Susan Collins, but it does not have much recent history of electing conservative ones. Still, the presence of an independent candidate in the race, Eliot Cutler, may be eating into Ms. Mitchell’s vote share, and Maine is an idiosyncratic and sometimes contrarian state. Mr. LePage probably does need to be considered the favorite, therefore, unless other polling firms weigh in and convey a different impression of the race.

Another state with sparse polling is Vermont; Rasmussen Reports is the only firm to have surveyed the state, and only on a couple of occasions. But a new poll from Rasmussen shows the Democrat, Peter Shumlin, with a narrow lead, after previously having trailed the Republican Brian Dubie by a substantial margin. Mr. Shumlin was declared the winner of a recount in the Democratic primary last week, in which four Democrats each finished with 21 to 25 percent of the vote. Polling results can sometimes be erratic immediately before or immediately after primaries, and so the poll should probably be interpreted cautiously — although it is also not uncommon for a fundamentally new dynamic to emerge in a race after a primary. In any event, the model now regards Mr. Shumlin as a 3-to-1 favorite, in spite of having been the underdog before.

Finally, a note about the forecast in New York: we are now modeling the state as a three-way race, with Andrew M. Cuomo on the Democratic ballot line, Carl P. Paladino on the Republican ballot line, and Rick Lazio — who lost to Mr. Paladino in Tuesday’s Republican primary — representing the Conservative Party. There has been only one poll with this configuration of candidates; it had Mr. Cuomo with 56 percent of the vote, Mr. Paladino with 14 percent and Mr. Lazio with 16 percent. Although the gubernatorial model is fairly sophisticated in its handling of three-way races, such an arrangement — one candidate with a huge lead while two others in the teens — is fairly unusual. The forecast will benefit from further polling; what is clear for now is that Mr. Cuomo is the overwhelming favorite.

What's Next

About

This is an archive of posts from FiveThirtyEight, a blog founded by Nate Silver in 2008 and devoted to rigorous, data-driven analysis of politics, polling, public affairs, sports, economics, science and culture, from August 2010 through July 2013.